Teletype silencing cabinet



Feb. 8, 1955 c. l.. MONTGOMERY TELETYPE SILENCING CABINET 2 Shets-Sheetl Filed April 12, 1954 IN VEN TOR.

kW/e5 .L Manga/772W Feb. 8, 1955 c. L. MONTGOMERY TELETYPE SILENCINGCABINET 2 Sheets-Sheet 2 filed ADIil l2, 1954 INVENTOR. Waff/e5Manga/wey BY j Arme/ven United States Patent O 2,701,618 TELETYPESILENCING CABINET Charles L. Montgomery, Topeka, Kans. Application April12, 1954, Serial No. 422,489 6 Claims. (Cl. 181-33) This inventionrelates to means for silencing teletype machines and refers moreparticularly to a combination silencing and Ventilating cabinet for bothconsole and table model teletype machines.

Many attempts have been made to reduce the noise levels produced byteletype machines but these efforts have been essentially unsuccessfulto date. When one or a plurality of these machines is employed in anoffice, the intermittent racket produced makes working conditions in thevicinity almost impossible. Previous efforts have involved closing upthe paper slot as well as securing an insulating medium to the inside ofthe teletype cabinet itself. Closing the slot alone does notsufficiently reduce the noise level, while lining the teletype cabinetfails because:

(a) The teletype mechanism gets hot and unless an air circulating systemis installed, the parts will be seriously damaged;

(b) The teletype cabinet absorbs vibration from the teletype mechanismand revibrates it;

(c) The lining packs and/or falls into the intricate mechanism of theteletype, causing malfunction and failure.

Therefore, an object of the present invention is to provide an insulatedteletype silencing and Ventilating cabinet for either full lengthconsole or table models of teletypes which will effectively reduce thenoise level thereof.

A further object is to provide such an insulated silencing andVentilating cabinet which offers ready access to the teletype forreplacement or repair without complete removal of the cabinet.

Another object is to provide a combination silencing and Ventilatingcabinet which is independent from the teletype mechanism and cabinet,which encompasses and almost completely dampens sound and othervibrations, s inexpensive, simple, attractive, practical and troubleree.

A further object is to provide such a silencing and Ventilating cabinetwhich completely encloses the teletype assembly, ventilates the teletypeby making the teletype assembly serve as an intake Ventilating duct andthe remainder of the silencing cabinet serve as an exhaust duct andprovides space in the exhaust duct for the accumulation of excessteletype paper.

Still another object is to provide such an insulated silencing andVentilating cabinet wherein a single source of suction may be employedto ventilate a plurality of such cabinets.

Other and further objects will appear in the course of the followingdescription.

In the accompanying drawing which forms part of the specification and isto be read in conjunction therewith and in which like reference numeralsindicate like parts in the various views:

Fig. l is a Aperspective View of a preferred forni of teletype silencingcabinet enclosing a console type teletype machine with the top closureof the silencing cabinet in raised position;

Fig. 2 is a side sectional View of the silencing cabinet of Fig. l withadditional parts in section;

Fig. 3 is a View taken along the lines 3 3 of Fig. 2 in the direction ofthe arrows;

Fig. 4 is a View similarto that of Fig. 3 but illustrates a modifiedform of silencing cabinet;

Fig. 5 is a side sectional View of a second modified form of teletypesilencing cabinet for a table model teletype assembly;

Fig. 6 is a View taken along the lines 6-6 of Fig. 5 in the direction ofthe arrows;

Fig. 7 is a top sectional view of one corner of .the window in the topclosure of the silencing cabinets; and

Fig. 8 is a Viewy taken along the lines 8-8 of Fig. 7 in the directionof the arrows.

Three modifications of the invention are shown in the figures aspreviously noted in the description of the iigures. The modificationsdeal primarily with variations in structure of teletype machine cabinetsand secondarily with variations in insulation placement and means of aircirculation.

The essential feature in all the modifications lies in the provision ofa sound absorbing box surrounding the teletype console or table andprinter to form an enclosure. The enclosure is adapted to fit againstand around the teletype structure and baflies are added to the structureif required so that there is created a partition within the enclosuredividing it essentially into two ducts for the purpose of Ventilationand air circulation. An air inlet is provided in one duct and means forexhausting the air from the enclosure is provided in the other duct. Theinlet and exhaust means are preferably positioned at the oppositeextremities of the interconnected ducts so that maximum air flow withinthe enclosure is provided. One of the ducts comprises essentially thebody of the teletype apparatus and the other the space between the backof the teletype apparatus and the rear wall of the enclosure. Theteletype assembly plus whatever added bafiies are required constitutethe partition within the enclosure which defines the two ducts.

There are two basic forms of teletype machines in general use, the typeAC-lS printer with standard table and the type AC-Zl console. Thepresent invention provides a Ventilating and silencing cabinet adaptablewith minor modifications to fit either type. The Figs. l, 2 and 3 showthe invention as applied to the type AC-2l console and Figs. 5 and 6show the invention as applied to the type AC-15 printer with standardtable. These modifications will be discussed separately in the aboveorder.

Referring to the drawings and more particularly to Figs. l, 2 and 3which illustrate a Ventilating and silencing cabinet embodying theinvention as applied to the type AC-Zl (full-length console type)teletype machine, the numeral 10 indicates the side wall of the console,11 the back wall, 12 the front wall and 13 the top wall. As the teletypeinternal mechanism is conventional, it is not shown in detail, but at 14is shown a cylindrical platen around which a work sheet or paper strip15 travels. The paper strip 15 emerges from the cabinet through paperslot 16 at the top of viewing plate 17 and conventionally passes overthe top 13 of the cabinet until it is cut or torn off. The rectifier 13of the teletype is shown in the cutaway of Fig. 2. The walls of theconsole conventionally extend almost to floor level but have air gaps11a and 12a of greater or lesser lengths therebetween. The consoletable, the front of which forms the lower portion of the front side ofthe teletype console l2, is mounted on rollers. This console table rollsout easily when the front door of the silencing cabinet is opened.

The Ventilating and silencing cabinet comprises n box fitting around theconsole having side walls 19, front wall 20 and rear wall 21. The wallsof the silencing cabinets are preferably of metal, especially aluminum.The front wall 20 is preferably formed as a door 20a with 'continuoushinge 22 and latches 23. Access to the front of the teletype console maybe had through door 20a and thc door is preferably of slightly greaterwidth than the console. Door 20a preferably does not reach to the floorlevel but has gap 2011 thereunder to serve as an air inlet forventilation. Side walls 19 are of substantially greater depth than sideWalls 10 of the console which provides a chamber 24 between the rearwall 1l of the console and the rear wall 21 of the silencing cabinetwhen the front of the console abuts the back of door 20a as iscontemplated in use. The box has a top closure Z5 mounted on continuoushinge 26 and having handle 27 for opening. Supports 28 on rear wall 21serve as rests for top closure 25 in open position. A viewing window isprovided in the front ofthe top closure to permit reading the teletypepaper 15 without opening the silencing cabinet.' The structure of themounting for the window is shown in Figs. 7 and 8. The window comprisesinterior 29 and exterior 30 glass plates, lpreferably of double strengthwindow glass. The internal plate 29 is secured to-a metal molding 31 byfitting into rubber strip 32 which lies in channel 33 of the molding.Flange 34 of the molding is secured to the top closure wall 25 by screws35. Exterior plate 30 1s held to molding 31 by channel strip 36 which isgripped on one side 36a by upper channel 37 of molding 31. Dead airspace 38 lies between the plates and aids in the sound insulation.

The sound suppressing cabinet is lined throughout (all sides and the topclosure) preferably in the following manner: the two sides and the frontdoor of the base section are lined with thick (approximately 11/2 inch)sound proofing material (preferably long textile-type glass berinsulation enclosed in bats). All the inside s urfaces, except thewindow area, of the top section are lm ed with the same type acousticalmaterial approximately l'lnch thick. The rear wall of the base sectionis lined wlth the same type sound proofing material approximately 1/2inch thick. These insulation bats are faced with suitable material (4vinyl film, fire resistant muslin, etc).

The box is constructed to be of such a width that when it is enclosingthe console the lit between the side walls of the console and theinsulation pads is substantially air tight. It is contemplated also thatthe front wall 12 of the console abut the front pads on door a insubstantially airtight relationship and angle iron stop members 39 (bestseen in Fig. 3) are provided to maintain this relationship when thecabinet is in position around the console. The bottom edge of the topclosure has a sponge rubber shim or hollow strip 40 along itscircumference to seal the space between the top and base parts of thesilencing cabinet for air and sound leakage. Positioned in the chamber24 between the rear wall 11 of the con sole and the rear wall 21 of thebox is blower 41 having motor portion 41a and fan 41b with outlet 41Cbest seen in Fig. l. Electrical leads 42 furnish power to the motor. Theblower 41 may be positioned in any desired manner in the chamber 24, butthe position illustrated is preferred because the motor 41a is outsidethe chamber 24 where it is cooled by outside air and the outlet 41C ispositioned as near to the bottom of the chamber 24 as feasible; thus theblower does not obstruct the channel or the fall of teletype papertherein.

It will be observed that with the exception of the gaps between thewalls of the console and the floor (only gaps 11a and 12a at front andrear being visible in Fig. 2) the stationing of the silencing cabinet inclosed position (front door and top closure) surrounding the consolecompletely encloses the console. Rubber shim 43 is provided to seal reargap 11a to the floor and the side gaps are either sealed automaticallyby the side wall 19 insulation pads or shims (not shown) may be used toseal them, and thus an enclosure is provided with a partition therein(the rear wall of the console plus shim 43) which divides the enclosureinto two ducts interconnected at their upper ends with an air inlet inone duct and air exhausting means in the other. The air inlet comprisesthe juxtaposed slot 20b and gap 12a leading to the interior of theteletype console which comprises the first duct. The chamber 24, thesecond duct, also provides space for the accumulation of excess teletypepaper. The interconnection of the two ducts is above the top of theconsole through the paper slot of the teletype.

The air cooling system is necessary to reduce the temperature inside theteletype console, which rises considerably with the installation of thesilencing cabinet. The cooling system operates in the following manner:The air enters under the front door of the silencing cabinet and gap12a, goes up through the center of the teletype cabinet past therectifier 18, into the top part of the teletype cabinet; through theteletype mechanism and out through the paper slot in the top of theteletype machine; back over the top and down the back of the console,between the console and silencing cabinet and finally out near thebottom and back of the silencing cabinet through the blower. The path ofthis air flow is indicated by the arrows in the figures. It isappreciated that variations in structure of the console might be made bythe manu* facturer. However, the side walls and front of the silence ingcabinet may be varied to seal in airtight manner these walls along theirlength and appropriate sealing members provided to seal the rear wall ofthe console so a substantially continuous partition is provided from theoor to the upper portion of the console to deiine the Ventilating ductas described. Similarly, somewhat varying pro- -vision such as ports ofvarious sizes in console and door 20a could be made to obtain ingress ofair into the console front should gap 12 not be available. The importantfeature of the invention is the provision of the enclosure partitionedinto ducts with inlet and outlet entrances into the ducts.

Referring now to Figs. 5 and 6 illustrating the type AC-15 printer(table model), it should be understood that considerable variation maybe encountered in the size of the table mounting this model printeralthough a standard size table is generally provided. The size and shapeof the silencing and Ventilating cabinet will be altered in conformancewith the size and shape of the table or stand on which the printer ismounted or supported.

Numeral 44 indicates the side walls of the teletype printer, 45 the rearwall, 46 the front wall and the top wall 47. Again, the teletypemechanism being standard, it is not shown in detail but paper strip 48is shown emerging from a slot at the top of the viewing plate (not shownbut similar to slot 16 in the embodiment illustrated in Fig. l) andpassing over the top of the printer. The rectifier 50 is shown mountedbelow the printer on rear plate 51 of a stand or table. The printerrests on table top 53 and the rear plate 51 is attached to the undersideof the top 53 between legs 54. Table 52 typically has a plurality ofholes 55 in the top 53 thereof for passage of cable to the printer andthese are generally large enough to permit passage of the required airflow. Additional holes may be provided in the top or felt or similar padremoved if required. These holes, of course, must be located under theprinter. Shield or baille 56 extends from floor level up to the loweredge of the table top 53 and is usually of greater width than top 53.There are generally no casters on the base of the table for the type 15teletype. The bottom of the printer lies essentially ilush with the top53 of the table and a strip of sealing material (sponge rubber shim orsimilar) may be applied either on top or on the front side near the topof shield 56 if desired or needed (not shown).

The Ventilating and silencing cabinet comprises a box fitting around thetable and printer having side walls 57, front wall 58 and rear wall 59.Front wall 58 is preferably formed as a door 58a with continuous hinge60 and latches 61. Access to the front of the printer may be had throughdoor 58a and door 58a is preferably of slightly greater width than thetable top 53. Door 58a preferably does not reach to oor level but hasgap 581; thereunder to serve as an air inlet for ventilation. Side walls57 are of substantially greater depth than the depth of table top 53which provides a chamber 62 between the rear wall 45 of the printer, theshield 56 and the rear wall 59 of the silencing cabinet. Note that it isnot absolutely necessary that the printer rear wall be next the rearedge of top 53 but a smoother paper fall will be provided if it is so.The box has a top closure 63 mounted on continuous hinge 64 and havinghandle 65 for opening. Supports 66 on rear wall 59 serve as rests fortop closure 63 in open position. The viewing window has the samestructure as detailed previously and will not be again described. Theinsulating cabinet is lined in the same manner as the cabinet for thetype 21 machine and this will not be again described.

The box is constructed to be of such a width that when it is enclosingthe table top 53 the fit between the side edges of the table top and theside wall insulation pads is substantially airtight relationship. Thetable may be positioned firmly as described by a number of methods but,in the preferred form, shield 56 is attached to side walls 57 at adistance from the rear wall 59 of the box so that it abuts the reartable legs 54 when the table is properly positioned in the box. If it isdesired to attach the shield 56 to the table instead of the side walls,the shield 56 is made at least as wide as table top 53 and aoor 67 maybe provided in chamber 62 to abut the bottom portion of the shield 56.Thus the volume beneath the table top 53 is sealed off at all times whendoor 58a is closed except for air inlet 58b. The bottom edge of the topclosure 63 is sealed as previously described and a blower 68 is providedhaving motor 68a, fan 6811 and outlet 68e also as previously describedin the description of the cabinet of Figs. l, 2 and 3.

By enclosing the table top 53 on three sides and providing shield 56 toseal the fourth side as described, the stationing of the silencingcabinet in closed position completely encloses the table and printerwith the exception of air gap 58b under the door 58a. This provides anenclosure with a partition therein (the shield 56, table top 53 andprinter walls) which effectively divides the enclosure into two ductsinterconnected at their upper ends, with an air inlet in one duct andair exhausting means in the other. The rst duct comprises the enclosedunderside of the table, the holes in the table and the inside of theteletype printer and the second duct comprises the chamber 62 betweenthe shield 56 and the rear wall 59 of the box and the volume surroundingthe printer casing above the table top 53. The interconnection of thetwo ducts is above the top of the printer through the paper slot 49.

The arrows in Fig. 5 indicate the air flow route which enters under thefront door of the silencing cabinet, under the front end of the teletypetable, then through the holes in the table top into the teletypecabinet, out through the top of the teletype cabinet via the paper slot,down between the printer cabinet and the back of the silencer cabinet,then lower between the vertical shield and the back of the silencingcabinet, into the blower and out through the outlet.

In the case of the type 21 or similar full length console type teletypemachine, the air ow simply entered the console at the bottom and cameout the paper slot at the top and down the back of the console and thenout the bottom. With the type 15 or similar table model, there is noconsole from the table top to the floor, so it is necessary to seal offthe space below the table top 53 and in front of the back edge of thetable. The table top 53 itself seals against the front 53 and both rightand left sides 57 of the silencing cabinet and the vertical shield 56seals off the back side of the table from the table top to the oor. Inthis manner, the air currents must go through the holes in the table top53, into the printer cabinet and then through essentially the same routeas for the type 21 console for the remainder of the cycle.

Fig. 4 is designed to show a modification of the silencing cabinet forthe console type teletype machine and shows the cabinet with the topclosure removed. In this view like numbers are employed to show likeparts to the views in Figs. 1, 2 and 3. Thus, 10, 11, 12 and 13 indicatethe side, back, front and top walls of the console, respectively, 15 thepaper, 16 the paper slot and 17 the view plate. 19, 20 and 21 indicatethe side, front and rear walls of the silencing cabinet, with 22indicating the door hinge and 23 a latch thereof. The cabinet walls areinsulated as indicated in the description of Figs. 1, 2 and 3 with theexception that the single thickness of insulation on rear wall 21 isreplaced by thick insulation panels 69 which extend from the rear wall21 to the back wall 11 of the console thereby defining the lateral edgesof chamber 24 which is at least greater than the width of paper strip15. In this modification also is illustrated the air exhaust systemcontemplated when a plurality of silencing cabinets are ernployed. Anexhaust pipe 70 penetrates rear wall 11 and connects with chamber 24.The other extremity of pipe 70 connects with suction pipe 71 which leadsto a suction source (not shown). The air flow in this modification isthe same as that described for the console systern of Figs. 1, 2, 3 andall other structures are the same as in those gures with the exceptionof the omission of angle iron stop members 39 and the blower assemblywhich are omitted.

Thus it is seen that a teletype silencing and Ventilating cabinet hasbeen provided for both console and table model teletype machines whichcompletely enclose the said machines and, furthermore, enclose theteletype machines and their mountings so as to effectively partition theenclosing cabinet into two interconnected ducts, one comprising theteletype assembly and having an air inlet, the other comprising theresidual volume of the silencing cabinet and having air exhausting meanstherein, the ducts being interconnected by the paper slot in the upperportion of the teletype machine. In addition, this silencing cabinet hasprovision for receiving excess teletype paper, a viewing aperture, topand side access doors, and accomplishes all of the objects previouslyset out therefor.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

l. An insulated sound absorbing cabinet for teletype machines comprisingan insulated enclosure surrounding the machine, a partition dividing theenclosure into separate ducts interconnected at only one end thereof,one duct having 'therein the teletype machine, an air intake opening ina wall of one duct and air exhausting means in a wall of the other duct.

2. A cabinet as in claim 1 wherein the air intake opening and airexhausting means are positioned so as to provide for maximum travel ofair therebetween.

3. An insulated sound absorbing cabinet for table model teletypemachines which models include a teletype machine mounted on a tablehaving a top and legs, the table having a hole in the top thereofbeneath the teletype machine, comprising an insulated enclosuresurrounding the teletype machine and table and abutting the table top onthree sides, a partition dividing the enclosure and forming with thetable top and teletype machine two separate ducts interconnected at theupper end thereof, one of said ducts extending through the teletypemachine and the other of said ducts being external of the machine butwithin the enclosure, an air intake opening in a wall of one duct andair exhaust means in a wall of the other duct.

4. An insulated sound absorbing cabinet for essentially lioor lengthconsole model teletype machines, comprising an insulated enclosuresurrounding the machine and abutting the console on three sides, theremaining side of the console forming a partition dividing the enclosureinto separate ducts interconnected at the upper end thereof, an airintake opening in a wall of one duct and air exhaust means in a wall ofthe other duct.

5. An insulated sound absorbing and Ventilating cabinet for teletypemachines of the type having a teletype mechanism enclosed within ahousing, said housing being provided with openings at the top and bottomfor the ingress and egress of air, comprising an internally insulatedenclosure surrounding the machine and including means forming with themachine housing an air exhaust duct open to the atmosphere andcommunicating only with the opening at the top of said housing, saidenclosure being provided with an air intake communicating only with theopening at the bottom of said machine, and forced air exhaust meanslocated in said exhaust duct for drawing air through said intake andthrough said machine.

6. An insulated sound absorbing and Ventilating cabinet for teletypingmachines of the type having a teletype mechanism enclosed within ahousing, said housing being provided with openings at the top and bottomfor the ingress and egress of air, comprising an insulated enclosuresurrounding the cabinet having a cross-sectional area greater than thatof the housing, means for maintaining the housing tightly against atleast one of the walls of said enclosure thereby to provide a ductwithin said enclosure between another wall of the enclosure and anadjacent wall of said housing, said enclosure being so formed as toprovide open communication between the opening at the top of saidhousing and said duct, intake means for communicating air from outsidesaid enclosure to the opening at the bottom of said housing, and forcedair exhaust means in said duct communicating with the atmosphere to drawair upwardly through said housing and to discharge said air to theatmosphere.

References Cited in the file of this patent UNITED STATES PATENTS1,910,981 Bescherer May 23, 1933 2,155,495 Kuntz Apr. 25, 1939 2,160,847Eitzen June 6, 1939 2,517,147 Vee Aug. 1, 1950 2,628,550 King Feb. 17,1953

